Separation of carbon black or fine powders from gases



Aug. 18,1942. s. c. CARNEY SEPARATIOY 0F CARBON BLACK 0R FINE POWDERS FROI GASES Filed June 26, 1939 2 Sheets-*Sheet 1 INVENTOR S. C. CARNEY BY M' A r EYs Aug. 18, 1942. s. c. CARNI-:Y

SEPARATION 0F CARBON BLACK 0R FINE POWDERS FROMY GASES 2 Sheets-Sheet 2 Filed June 26, 19159 INVENTQR I S. C. CARNEY Y i l` We Aus. 18 i;

'A UNITED 1 "PATENT oFFlcEjj H im Ni smul-c. omer, assomme, om.,m ai

Phillips Petroleum Company, a corporation of application .rune 26,1939, sexismo. 231,294

' z claim. (ci. :is-su) The present inventionv relates to a process of separating carbon black'or any other iine, dusty powderwhich is entrained as fine dust in a stream ot gas or air. Its purpose is similar to well know devices 'in vthe art such asbags. cyclone separators, Cottrell precipitators,'etc.l In recent years most carbon black plants have been equipped with some process for increasing the density of the raw black by pelletingor granulating, as for example, by use ofmy pelleting Black so vprepared is known` in the trade as dustlessf Though it is` relatively dustless as compared with the original material, the pelleting plants themselves are to a layman far from dustless. It has occurred to operators of suchplants that it a reduced pressure' equal to one or two inches of water were maintained in the pelleting or granulating apparatus and its necessary sieves and conveyors, dust incident to the pelleting process could be prevented from escaping into the building.- But evenwhen exhaust fans for this purpose have been linstalled but little relief was obtainedbecause of the well known ineiiiciency of bag flltersin collecting the very iine carboni?q Thereare also known processes for producing carbon black from gas by decomposition which leaves the carbon entrained in the gas mixture concurrently produced. Y In these, cyclone, bag f and Cottrelll precipitators are used. The cyclone is very ineillcient and the gases must be cooled to a low temperature when bags My process uses as a illter medium* the socalled granulated. or agglomerated carbon black such as is now being producedby many plants.

-'The advantages of the present process and apparatus over known processes and -1 apparatus 40 is simplicity, low cost and self-cleaning. Ascompared with cyclone orbag separators, it more completely removes the-carbon. As compared to the Cottrell precipitator, it-'is less eifective but more suitable for small-installations and for those 45 cases, frequent with carbon black, where the high eiliciency oi the Cottrell process is-not required.

The object oi' the present 'invention is to use agglomerated or .pelleted carbon black as a ill face of the moving carbon granules in container tering mediumtoremove-thelight ilocculantcar 5 I and the relatively clean air is discharged bon black from a stream of air.

It is a further object of the present invention i to use agglomerated orp'elleted lcarbon black as a filtering medium to remove carbon black from -in the decompositionprocess of making carbon black.

Other objects and advantages ofthe invention will be apparent during the course of the following description.

10 Figure 1 shows an elevational view partly'in' process, copending application. Serial No. 259,065 iiled February 28, 1939. 'l

section, of the apparatus used in the process of separating carbon black from dust, v

Figure 2 shows an elevational view, partly in section, of apparatus combining the ltering 15 process with apelleting process. Y

the drawings, wherein for the purpose of illustration, is shown' a preferred embodiment of myv invention, Figure 1 shows an installation suitable for the simpler case of relatively vsmall 2 volume of air or other gas as would result from maintaining reduced pressure by an exhaust fan on the mechanism of an agglomerating process, for examplethat of my copending application SerialV No. 259,065, led February 28, 1939. ,The

numeral I represents a chamber of suitable shape and size with bottom 2 having a slope equal to or greater than the angle of repose oi' the carbon aggregates used as the illter medium. In operation, itis automatically kept iilled to the level 3' 30with aggregates commercially free from dust preferably those which have been sifted from a commercial product `as greater than the maximum size and which are thus moving'toward further processing, .for example, to be brokenV down in the seedmill of -my copending application above mentioned.

The aggregates are supplied continuously to chamber I through the pipe 4 whichconnects the pipe i there enters'a stream of air induced o by the suction of exhaust fan 0. The line 5 connects to'various umts of the pelleting process and the volume of air drawn through it` is such as entire pelleting' apparatus and will carry with it the .ne carbon dust 'incident to a pelleting through'the pipe l.- By any suitable'automatic arrangement, carbon` granules which havebeen coated with dust are withdrawnl through pipe l to be further processed... The automatic 'means u disclosed in the drawing shows the container I into apelleting process of any type. 'Through f will maintain a slightly reduced pressure on the' mounted on flexible spring means 9 with flexible sections III, I-I, and I2 included in the pipes l, 5, and 'I. These sections are well known in the art and may be made of fabric with an internal helical spring coil as a reenforcing.' Discharge pipe 8 is iixed in a stationary position and makes junction with chamber I by the slide valve I3. If carbon pellets flow out through pipe 8 at too great a rate, the weight of chamber I is reduced as its contents become less and springs 9 are so tensioned that they extend lifting chamber I with them and thus reduce the opening at slide valve I3. The rate of control shown is to be taken as a preferred example only as numerous other means are possible for eiiecting the same result and applicant does not wish to limit himself to the one means here shown.

Figure 2 shows the same invention with inclusion of the step of continuously reconditioning the carbon aggregates of the iilter bed. It is adapted for the first means of recovery of carbon black entrained in a stream of gas as produced by a decomposition process, as distinguished from the known channel process. In eiect, it combines the separation from the gas stream with a pelleting process. By this means the low density black has its density brought up in the separating process.

The numeral I represents a cylindrical chamber having in practice a diameter on the order of six feet and is suitably inclined from the vertical position with reference to the angle of repose of carbon agglomerates. It is mounted on trunnions and arranged to rotate about its central axis. 'I'he pipe 2 carries gas containing entrained fine carbon black into the space 3 in the end of the chamber. `The pipe 2 has a swivel joint 4 which -allows the chamber I to rotate and the within the space 3 is so covered by cup 5 that carbon aggregates will not roll into pipe 2 from the chamber I. 1 The lower end of the Archimedes spiral tube 'I is represented at 6 and the tube 1 encircles the outside surface of the chamber I and the opening 6 communicates with the inside of the chamber I. The upper end of the spiral tube 'I again communicates with the interior of chamber I at 8. Thus the extremely ne material entering the chamber I through the air stream passing through 2 from the decomposition process is caught on the surface of the carbon agglomerates with which the Ichamber I is y pipe 2 to remain stationary. The end of pipe 2 initially iilled. As opening 6 comes to the bottom y position, agglomerates will ow into the Archimedes spiral and will cease flowing as opening 6 comes to the upper position. Only the lower part of each coil of the spiral thus contains agglomerates which are carried upward and discharged back into the top of the chamber I through'opening 8. f On the passage upward through the spiral the iine dust collected in the bottom of the chamber' I from the gas stream will be tightly agglomerated on the previously formed granules and when reintroduced at the top constitute a fresh filter bed constantly fed downwardly. The mechanism of this agglomeration is the same as the Archimedes spiral described in my copending application'Serial No. 274,003 filed May 16, 1939.

- Seed as described in this prior application may also be introduced at the top of the chamber I in Aamount suiiicient to form a commercial range of sizes. As the content of cylinder I is thus being added to from the gas stream and the added seed, it will continuously overflow into downpipe 9, the overow being the crude product which is removed from commercial iinishing and classication in the known manner.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the-shape, size and ar- `rangen'ient'of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims,

Having thus described my invention, I claim:

l. The process of separating from a stream of gas carbon black entrained therein as a dust and then continuously agglomeratingsaid separated 2. The process of separating from a stream of gas carbon black entrained therein as a dust and then continuously agglomerating said separated carbon black to form granules ofcarbon black which comprises, passing the stream of gas through a lter bed of granules of carbon black, removing from the bottom of`the filter bed a mixture of granules and raw carbon black, agglomerating the raw carbon black to the granules by subjecting the granules and raw carbon black v to vrelative movement while simultaneously elevating the mixture to the top of the lter bed and discharging ythe granules from the agglomerating and elevating step onto the top of the filter bed.

SAMUEL C. CARNEY. 

